content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.interop.internal.consumers;
  
  import org.reactivestreams.Subscriber;
  
  import hu.akarnokd.reactivestreams.extensions.FusedQueueSubscription;
  import io.reactivex.common.Disposable;
  import io.reactivex.common.internal.disposables.DisposableHelper;
  import io.reactivex.observable.CompletableObserver;
  
  public final class SubscriberCompletableObserver<T> implements CompletableObserver,
  FusedQueueSubscription<T> {
      final Subscriber<? super T> subscriber;
  
      Disposable d;
  
      public SubscriberCompletableObserver(Subscriber<? super T> observer) {
          this.subscriber = observer;
      }
  
      @Override
      public void onComplete() {
          subscriber.onComplete();
      }
  
      @Override
      public void onError(Throwable e) {
          subscriber.onError(e);
      }
  
      @Override
      public void onSubscribe(Disposable d) {
          if (DisposableHelper.validate(this.d, d)) {
              this.d = d;
  
              subscriber.onSubscribe(this);
          }
      }
  
      @Override
      public void request(long n) {
          // ignored, no values emitted anyway
      }
  
      @Override
      public void cancel() {
          d.dispose();
      }
  
      @Override
      public boolean offer(T element) {
          throw new UnsupportedOperationException("Should not be called!");
      }
  
      @Override
      public T poll() throws Throwable {
          return null;
      }
  
      @Override
      public boolean isEmpty() {
          return true;
      }
  
      @Override
      public void clear() {
          // deliberately no-op
      }
  
      @Override
      public int requestFusion(int mode) {
          return mode & ASYNC;
      }
  }
  